TP 

753 
C8 


Ub-NnLr 


GIFT 

OF 

COX'S  GAS-FLOW   COMPUTER, 


FOR    LOW'  PRESSURES. 


This  Computer  solves  Professor  Pole's  well-known  formula  for  the  flow  of 


X  w 


Discharge  in  cub.  ft.  per  hour=c 

A 

Where  d  =  diameter  of  pipe  in  inches, 

px  =  initial  pressure  in  inches  of  water, 
p2— terminal  pressure  in  inches  of  water, 
1  =length  of  pipe  in  yards, 
w  —specific  gravity  of  the  gas  when  air  =  1. 
c  =a  constant  varying  from  1000  to  1350. 


To  Find  the  Discharge  from  a  Pipe  and  the  Required  Size 

(1).     Set  the  specific  gravity  of  the  gas  opposite  the  selected  constant; 

(2).     Bring  the  difference  of  pressure  (pt— p2)  opposite  the  given  length  of  pipe; 

(3).     Opposite  any  diameter  of  pipe  will  be  .at  once  found  the  discharge  in  cubic  feet  per 

hour ;  and 
(4).     Opposite  any  desired  discharge  will  also  be  found  the  required  diameter  of  the  pipe. 


To  Find  the  Difference  of  Pressure,  p±— p2. 

(1).     Set  the  specific  gravity  of  the  gas  opposite  the  selected  constant ; 
(2).     Bring  the  diameter  of  pipe  opposite  the  desired  discharge  in  cubic  feet  per  hour ; 
(3).     Opposite  the  given  length  of  pipe  find  the  required  difference  of  pressure  between  the 
ends  of  the  pipe. 

The  Section  Scale. 

If  equal  quantities  of  gas  are  discharged  from  a  main  at  several  equally  distant  points, 
as  in  the  case  of  houses  in'  a  street,  the  volume  of  gas  flowing  per  minute  through  each 
succeeding  section  of  the  main  will  be  smaller,  resulting  in  a  DECREASE  of  the  total  friction 
pressure,  or  an  INCREASE  of  the  total  discharge  for  the  same  pressure. 

The  Section  Scale  shows  at  once  the  effect  of  such  DISTRIBUTED  discharge  for  any 
number  of  sections. 

To  Use  the  Section  Scale. 

To  FIND  THE  TOTAL  DISCHARGE.  Set  the  radial  edge  (=1)  to  the  diameter  of  the  pipe, 
then  opposite  the  number  of  sections  find  the  corresponding  increased  discharge 
of  ALL  the  sections.  The  length  to  be  used  is  the  total  length  of  pipe,  not  that 
of  a  section. 

To  FIND  THE  PRESSURE.  Set  the  radial  edge  to  the  diameter,  then  turn  the  disk  round 
with  the  section  scale  until  the  number  of  sections  is  opposite  the  required  total 
discharge  of  all  the  sections.  Now  opposite  the  total  length  of  pipe,  find  the 
diminished  pressure  of  ALL  the  sections. 


Price  of  the  Computers,  in  Cloth  Case,  6^x8  inches,  $2.50  Each,  Net. 

*ddress     WILLIAM    COX, 

ROOM  924,       25   BROAD  STREET,       NEW  YORK  CITY. 


Cox's  High-Pressure  Fluid 


This  Computer  solves  the  following  formula,  which  is  applicable  to  Gas,  Air  and  other 
elastic  fluids,  flowing  through  long  pipes  with  high  initial  pressures  :  — 


Discharge  in  cubic  feet  per  hour^  —  QQ  o       /     x(Pi     Pa  ) 
at  atmospheric  pressure)  ~  \f        L  x  w 

where  d  —  diameter  of  pipe  in  inches, 

Pi=  absolute  initial  pressure  in  pounds  per  square  inch, 
P2=  absolute  terminal  pressure  in  pounds  per  square  inch, 
L  =  length  of  pipe  in  miles, 
w  =  specific  gravity  of  the  fluid  when  air  =  1. 

To  Find  the  Discharge  from  a  Pipe  and  the  Required  Size  of  Pipe. 

(1).     Set  the  specific  gravity  of  the  fluid  opposite  the  length  of  pipe ; 

(2).     Bring  the  DIFFEKEXCE  of  the  initial  and  terminal  gauge  pressures  opposite  the 

SUM  of  the  initial  and  terminal  gauge  pressures  ; 
(3).     Opposite  any  diameter  of  pipe  will  now  be  found  the  discharge  in  cubic  feet  per 

hour  at  atmospheric  pressure  ;  and 
(4).     Opposite  any  desired  discharge  will  also  be  found  the  required  diameter  of  pipe. 

To  Find  Suitable  Initial  and  Terminal  Pressures. 

(1).     Set  the  specific  gravity  of  the  fluid  opposite  the  length  of  pipe ; 

(2).  Bring  the  diameter  of  the  pipe  opposite  the  desired  discharge  in  cubic  feet  per 
hour  ; 

(3).  All  coinciding  lines  of  the  scales  of  sum  and  difference  of  initial  and  terminal  gauge 
pressures  will  now  give  the  desired  result.  After  selecting  any  such  coinciding  lines,  find 
the  initial  pressure  from  sum  -f  difference  and  the  terminal  pressure  fiwn  sum-difference 

thus,  suppose  "sum"=  80,  and  "difference  "=  20,  then  initial  pressure  =  50,  and  termi- 
nal pressure  =  30  pounds.  A  little  practice  will  soon  render  the  solution  of  this  problem 
easy.  From  the  nature  of  the  formula  it  is  not  possible  to  put  it  into  simpler  shape, 
whilst  for  arithmetical  solution  it  is  very  much  more  tedious. 


Price  of  the  Computers,  in  Cloth  Case,  6^x8  Inches,  $5.00  Each,  Net. 
Address, 

WILLIAM  cox, 

ROOM  925,  25  BROAD  STREET,  NEW  YORK  CITY. 


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UNIVERSITY  OF  CALIFORNIA  LIBRARY 


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400 


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200 


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coxy 

C    A   S-F    LOW 

COMB-UTER. 


Oopy right,  1894,  by 

WILLIAM    COX, 

NEW  YORK. 


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